The mosquito population has been higher than normal in many areas of the nation, some experts say.
A combination of drought, heavy rain and heat has translated to higher numbers of the bug.
Jonathan Day at the University of Florida told the Associated Press that the worst problem may be in the Southeast, where some areas are receiving three years' of bugs at one time.
He says after two years of drought, incredibly heavy rain came through this year.
As mosquito eggs don't often get wet enough to hatch during dry spells, the rains revived the eggs, along with the normal batch.
Parts of Connecticut, Minnesota and central California have also seen populations several times larger than normal.
Mosquitoes can spread disease.
Three cases of dengue fever were diagnosed in Martin County last week.
Last year, there was a record number of deaths due to West Nile, but this year, experts say, appears to be milder.
Worldwide, in areas outside of the United States, mosquito-borne diseases can kill far more people than sharks, snakes and bears combined.
There are more than 600,000 deaths from malaria every year in poorer countries.
To help prevent mosquito bites, wear light-colored clothing, long sleeves, use bus spray and remove standing water.
As small as a thimbleful can attract mosquitoes.